1. Field of the Invention
The present invention relates to a test apparatus testing a device under test such as a semiconductor circuit, a timing generator provided in the test apparatus, and a program making the test apparatus function.
2. Description of Related Art
When conventionally testing a device under test, there has been a method of inputting a test signal into the device under test and comparing an output signal output from the device under test with an expectation pattern in order to decide the good or bad of the device under test. In this case, the output signal output from the device under test is sampled by means of a strobe signal with a desired phase, and then a sampled result is compared with the expectation pattern. Moreover, in order to measure a waveform of an output signal output from the device under test, there has been a method of sampling the output signal by means of a strobe signal of which a phase for the output signal is changed by degrees.
In this manner, when testing a device under test, it is necessary to generate a strobe signal having a desired phase difference for an output signal output from the device under test. Conventionally, as an apparatus for generating a strobe signal with a desired phase, there has been known a circuit that delays a clock signal by means of a plurality of delay paths having a delay amount different from one another and selects a clock having a desired delay amount among the delay clocks delayed by each delay path to output the selected clock.
Now, since a related patent document is not recognized, the description is omitted.
However, a conventional apparatus has a problem that a circuit scale is large. For this reason, there is expected an apparatus that can generate a strobe signal having a desired phase difference for an output signal by means of a simple circuit configuration.